The invention relates to a compressor, in particular for a vehicle air conditioning system according to the heading of claim 1.
Conventional compressors for air conditioning systems, so-called air conditioning compressors, having a housing that surrounds a device for the transfer of the compressed medium. The pump unit, in the form of an axial piston pump, has at least one piston that can reciprocate within a cylinder block, and a swash plate rotating around a rotational axis, working in combination with a non-rotating take-up plate located within the compressor housing, which is connected to the pistons. The swash plate is coupled to the drive shaft via a carrier. The take-up plate rests upon a support device on a non-rotating thrust bearing. The thrust bearing serves to intercept the torque that is transferred from the rotating swash plate to the take-up plate. Normally a compressor of the type described here has several pistons. These transfer the medium to be compressed from a suction area to a compression area. The forces required for the compression of the coolant are very high. They are transferred into the housing via the drive shaft, which gives rise to high air home/structure borne noise emissions. Familiar compressors of this type also have the disadvantage that the carriers surround the drive shaft or the transfer of torque from the swash plate takes place using pegs or by pressing. This leads to a relatively high space requirement. Furthermore, it has also become evident that compressors of the conventional type are of expensive construction and encompass many components in the area where the take-up plate is supported. Furthermore, the take-up plate is often weakened by the support device.
The object of the invention is to create a compressor of the type discussed here of simple and compact construction that gives rise to low air-borne/structure-borne noise emissions and in particular can be economically manufactured.
For the achievement of this objective a compressor is suggested that has the characteristics described in claim 1. It is characterised by the fact that the forces required for the compression of the coolant are principally carried in the inside of the compressor housing. To achieve this the housing is made up of two sections, which each have a clamping shoulder. The cylinder block, in which at least one of the pistons of the device for conveying the compression medium reciprocates, is clamped between these. The drive shaft of the device for conveying the compression medium is fixed in the cylinder block by a fixed bearing.
It is therefore possible to transfer the forces required for the reciprocal movement of the pistons and the compression of the coolant via the swash plate, which is rigidly connected to the drive shaft, into the drive shaft and therefore into the inside of the housing. From the drive shaft the forces travel into the cylinder block, which is clamped by the two housing sections. The lines of force only run via the small housing section that runs outside via the fixing point of the cylinder block. The radiation area for air-borne/structure-borne noise is therefore reduced to a minimum. Furthermore, the housing is stabilised by the fixing points of the two housing sections to such a degree that when the device for conveying compressed medium is in operation only low vibrations occur at this point, greatly reducing the emission of noise.
Alternatively, or in addition to the above mentioned measures, it is suggested that the carrier and the drive shaft are fastened together by adhesionxe2x80x94preferably by welding, soldering and/or gluingxe2x80x94or manufactured as a single piece. This type of design makes it unnecessary for the drive shaft to be surrounded by the carrier, so less space is required. It is also evident that due to this construction the swash plate can swing out further, meaning that the compressor can be shorter. According to the invention, the construction of the compressor can also be simplified in that the take-up plate support device encompasses one of these projections, constructed as part of the take-up plate, that works in combination with a single support element. The number of parts is thus reduced to a minimum. The support element has a first sliding surface that works in combination with a first bearing surface of the support bearing, upon which the take-up plate is supported, for example in the compressor housing. The projection and the support element are positively connected together via a second sliding surface, whereby, on the one hand, a secure retention of the support element onto the projection is ensured without the need for additional support elements and, on the other hand, the relative movement of the two sections on the sliding surface is possible without giving rise to high loading.
A compressor design is preferred that is characterised by the fact that the cylinder block has a rotating mounting flange. The height of this flange is much less that that of the cylinder block. The mounting area of the housing can therefore be greatly reduced, so that the sound emission area is extremely small.
Particularly preferred is a compressor design that is characterised by the fact that the two housing sections are welded together. The vibrations and pulsations emitted by the operating compressor are conducted directly by the welded area of the housing sections, which are therefore connected together in a particularly stable and low vibration manner. This leads to a reduction in noise emissions. Furthermore, assembly parts, such as flanges and screws fitted outside the compressor housing, can be avoided completely, thus avoiding the surfaces of parts, which could contribute to noise emissions. The pump is therefore very light and compact, which greatly reduces the total noise emission area.
Further advantageous developments are described in the other subclaims.